Low temperature distillation oven



, May 21, 1957 D. PETlT LOW TEMPERATURE DISTILLATION OVEN Filed Sept. 17, 1955 INVENTOE. DA IEL P5727 6 TTOPNE United States Patent 6 LOW TEMPERATURE DISTILLATION OVEN Daniel Petit, Paris, France Application September 17, 1953, Serial No. 380,881

2 Claims. (Cl. 202-215) The present invention relates to an oven for the treatment of carbonaceous matter and more particularly to a low temperature distillation oven having a retarding means in the main portion of the distillation chamber to retard at least a portion of the carbonaceous matter as it passes through said chamber.

In the prior art, internally heated ovens are known in which the product to be distilled and the heating fluids are mixed in the upper portions of the oven, the distillation taking place during the descent of the product in the oven. These ovens have been provided with inclined plate fixed to the inner walls of the distillation chamber to reduce the rate of descent of the fuel particles to be distilled in the oven. However, in these type ovens, a large portion of the fuel grains to be distilled are entrained in the rapidly moving stream of heating fluids and gases, arriving at the lower part of the oven without being completely distilled. As a result, the volatile-matter content of the coal grains and the finer coal particles are not the same.

The present invention eliminates these disadvantages by providing a device which permits the fuel grains to remain in contact with the hot fluids a sufficient time to be completely distilled, so that a homogeneous char is obtained.

One of the features of the present invention is to provide a distillation device which is separated into compartments, one compartment being principally for fuel grains to be distilled and another compartment being for the heating fluids and gases having entrained therein fine fuel particles.

Another feature of the present invention is to provide a distillation oven whereby the proportion of gases circulating in the compartments can be regulated.

Another feature of the present invention is to provide a distillation oven which permits a regulation of the quantity and size of carbonaceous matter to be introduced into the fuel grain distillation chamber.

Still another feature of the present invention is to provide a distillation oven which permits relatively high heating fluid and gas circulating rates and accordingly provides an oven which has a high efiiciency.

More particularly, the present invention provides a low temperature distillation oven comprising a main cok ing chamber; a mixing chamber communicating with said main chamber; a fuel inlet means in said mixing chamber; a heating fluid inlet in said mixing chamber; a fuel retarding chamber, through which the fuel grains are conducted, positioned within said main chamber, said fuel retarding chamber having upper and lower openings communicating with said main chamber, the side walls of said fuel retarding chamber and the side walls of said main chamber defining a chamber substantially surrounding said fuel retarding chamber through which gases having fine fuel particles entrained therein are conducted; a fuel bin communicating with said retarding chamber and adapted to receive fuel grains falling from the lower opening of said retarding chamber and a gas outlet in said main chamber below said annular chamber adapted to permit the gases having coal fines entrained therein to be swept out of the oven.

It will be obvious that various changes can be made by one skilled in the art in the arrangement, form, construction, and type of the various elements disclosed hereinafter without departing from the spirit or scope of this invention.

Referring to the accompanying drawing which schematically discloses a vertical section of an embodiment of the oven of this invention, a vertically elongated coking chamber 10 preferably of rectangular horizontal cross section is shown, having a mixing chamber 4 positioned above and communicating with said main coking chamber. A fuel bin 1 is positioned above said mixing chamber and has a distributor 2 and a suspension device 3 mounted in the lower portion thereof; a heating fluid inlet 5 is provided in one side of the mixing chamber 4. Positioned at the lower opening 6 of the mixing chamber are the inclined plate guides 7 and mounted directly below the guides 7 are the plates or gates 8 which can be oscillated on a horizontal axis. Mounted within the main coking chamber 10 is a second chamber 11 which serve asa retarding chamber for the fuel grains. The chamber 11 extends along the longitudinal axis of the main coking chamber and the walls of these two chambers define an annular chamber 17 which substantially surrounds the chamber 11. The walls of the inner chamber 11 are made up of a series of plates 18 which have integral therewith or connected thereto a plurality of overlapping, downwardly inclined plates 13. The plates 13 are so arranged that they serve as a means for the fuel or particles to rebound downwardly from plate to plate. The plates 18 can be either partially or completely closed on the sides and, in the preferred embodiment of the invention, are shown to be partially closed.

The inlet of the retarding chamber 11 is closed by two plates or gates 9, which can be oscillated on the horizontal axis 12. When the space between these gates is smaller, less gas circulates in the chamber 11. This same eifect can be obtained by oscillation of the plates 8 or by oscillation of both sets of gates so that the gates complete the effect of gates 8.

Positioned below the retarding chamber 11 is a fuel bin 14- and positioned immediately above the fuel bin at one side of the chamber 10 is the gas outlet 15.

In the operation of the oven, heating fluid is introduced into the mixing chamber 4 through inlet 5 and is brought into contact with fuel particles that have come from the bin 1 through the distributor 2. Since the fuel particles pass through the suspension device 3, they enter the mixing chamber 4 in a suspended state, permitting them to be mixed easily with the hot fluids entering at 5. As the mixture leaves the mixing chamber, it passes through the opening 6. The gases have a tendency to follow the path of least resistance, flowing through the openings located between plates 7, 8, and 9. It should be noted that since the gates 8 can oscillate on a horizontal axis, the width of the openings between the plates 8 and the inclined plates 7 and 9 can be increased or reduced at will. If the openings are increased, the quantity of gas flowing through the chamber 11 is reduced, and the quantity and rate of gases circulating in chamber 17 are increased. Consequently, a greater proportion of fines is entrained in these gases.

The gases with fines entrained therein are swept out of the oven through the gas outlet 15. The grain particles which have been directed into the retarding chamber 11 by guides 7 rebound downwardly on plates 13, finally to fall by gravity into bin 14. Since the circula- Patented May 21, 1951 arcane tion of gas in chamber 11 is relatively slight, the grains are not entrained and the retarding effect of plates 13 is not destroyed. Thus, the grains are distilled for a sufficient time under the required conditions.

In the usual operation of the oven, the distillation of the fine particles is practically instantaneous and that of the grains which pass through the retarding chamber 11 requires a longer time' By way of example, with a dry coal, the grains from almost 0 to /2 mm. are heated and distilled in less than one second; the grains from 1 2 to 3 mm. require about 10 seconds to be distilled under the same condition.

It is to be noted that the disclosed apparatus also can be used for the drying of carbonaceous or other matter as well a for distilling purposes.

The invention claimed is:

1. A low temperature distillation oven comprising a main coking chamber; a mixing chamber communicating with and arranged above said main chamber; a first inlet means for supplying fuel to said mixing chamber and a second inlet means for supplying a heating fluid to said mixing chamber; a fuel retarding chamber, through which the fuel grains are conducted, substantially coaxially positioned within said main chamber, said fuel retarding chamber having upper and lower openings communicating with said main chamber, the side walls of said fuel retarding chamber and the side Walls of said main chamber defining an annular chamber substantially surrounding said fuel retarding chamber through which gases having fine fuel particles entrained therein are conducted; a fuel bin communicating with said retarding chamber and adapted to receive fuel grains falling from the lower opening of said retarding chamber; a gas Outlet in said main chamber below said annular chamber adapted to permit the gases having coal fines entrained therein to be swept out of the oven; said fuel inlet means comprising a hopper having a fuel distributor positioned in the lower portion thereof and a suspension means positioned below said hopper adapted to feed the fuel in said hopper into said mixing chamber in suspended state; guide means positioned intermediate said mixing chamber and said main chamber adapted to funnel fuel grains into the retarding chamber; first adjustable gate means positioned between said guide means and the upper opening of said retarding chamber adapted to simultaneously adjust the size of the opening to said annular chamber and the size of the opening into said retarding chamber; and a set of second adjustable gates positioned at the upper opening of the retarding chamber, for further adjustment of the size of opening into the retarding chamber.

2. The apparatus of claim 1, wherein said retarding chamber has a plurality of spaced, downwardly inclined plates protruding inwardly from the inner walls adapted to retard to the fuel grains as they fall through said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,481,140 McEWen Ian. 15, 1924 1,854,300 Greene et a1 Apr. 19, 1932 2,338,573 Creelman Jan. 4, 1944 2,351,214 Kaufman et a1 June 13, 1945 2,438,199 Becker Mar. 23, 1948 2,448,223 Lantz Aug. 31, 1948 2,560,767 Huff July 17, 1951 FOREIGN PATENTS 9,355 Great Britain Mar. 9, 1905 235,627 Great Britain June 17, 1925 

1. A LOW TEMPERATURE DISTILLATION OVEN COMPRISING A MAIN COKING CHAMBER; A MIXING CHAMBER COMMUNICATING WITH AND ARRANGED ABOVE SAID MAIN CHAMBER; A FIRST INLET MEANS FOR SUPPLYING FUEL TO SAID MIXING CHAMBER AND A SECOND INLET MEANS FOR SUPPLYING A HEATAING FLUID TO SAID MIXING CHAMBER; A FUEL RETARDING CHAMBER, THROUGH WHICH THE FUEL GRAINS ARE CONDUCTED, SUBSTANTIALLY COAXIALLY POSITIONED WITHIN SAID MAIN CHAMBER, SAID FUEL RETARDING CHAMBER HAVING UPPER AND LOWER OPENINGS COMMUNICATING WITH SAID MAIN CHAMBER, THE SIDE WALLS OF SAID FUEL RETARDING CHAMBER AND THE SIDE WALLS OF SAID MAIN CHAMBER DEFINING AN ANNULAR CHAMBER SUBSTANTIALLY SURROUNDING SAID FUEL RETARDING CHAMBER THROUGH WHICH GASES HAVING FINE FUEL PARTICLES ENTRAINED THEREIN ARE CONDUCTED; A FUEL BIN COMMUNICATING WITH SAID RETARDING CHAMBER AND ADAPTED TO RECEIVE FUEL GRAINS FALLING FROM THE LOWER OPENING OF SAID RETARDING CHAMBER; A GAS OUTLET IN SAID MAIN CHAMBER BELOW SAID ANNULAR CHAMBER ADAPTED TO PERMIT THE GASES HAVING COAL FINES ENTRAINED THEREIN TO BE SWEPT OUT OF THE OVEN; SAID FUEL INLET MENAS COMPRISING A HOPPER HAVING A FUEL DISTRIBUTOR POSITIONED IN THE LOWER PORTION THEREOF AND A SUSPENDED MEANS POSITION BELOW SAID HOPPER ADAPTED TO FEED THE FUEL IN SAID HOPPER INTO SAID MIXING CHAMBER IN SUSPENSION STATE; GUIDE MEANS POSITIONED INTERMEDIATE SAID MIXING CHAMBER AND SAID MAIN CHABMER ADAPTED TO FUNNEL FUEL GRAINS INTO THE RETARDING CHAMBER; FIRST ADJUSTABLE GATE MEANS POSITIONED BETWEEN SAID GUIDE MEANS AND THE UPPER OPENING OF SAID RETARDING CHAMBER ADAPTED TO SIMULTANEOUSLY ADJUST THE SIZE OF THE OPENING TO SAID ANNULAR CHAMBER AND THE SIZE OF THE ADJUSTABLE GATES POSITIONED AT THE UPPER OPENING OF ADJUSTABLE INTO SAID RETARDING CHAMBER; AND A SET OF SECOND RETARDING CHAMBER, FOR FURTHER ADJUSTMENT OF THE SIZE OF OPENING INTO THE RETARDING CHAMBER. 